Automatic cam-grinding machine



July 3, 1928 R. K. ROWELL.

AUTOMATIC CAM GRINDING MACHINE" Filed March 6, "1926 14 Sheets-Sheet INVENTOR.

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ATTORNEY.

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AUTOMATIC CAM GRINDING MACHINE Flled March 6, 1926 July 3, 1928.

IN VEN TOR. R. K'Ro WELL.

A TORNEY.

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July 3, 192 8.

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R. K. ROWELL AUTOMATIC CAM GRINDING MACHINE Filed March 6, 1926 14 Sheets-Sheet 5 INVENTOR. R. E E0 WE'LL A TTORNEYI July 3, 1928. 1,675,466 K. ROWELL I AUTOMATIC CAM GRINDING MACHINE Filed March 6, 1926 14 Sheets-Sheet 6 Fig.7,

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R. K. ROWELL AUTOMATIC CAM GRINDING MACHINE Filed March 6, 1926 14 Sheets-Sheet 1N VEN TQR.

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R. K. ROWELL AUTOIATIC CAM GRINDING MACHINE Filed March 1926 14 Sheets-Sheet 5 'FiqlE.

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Filed March 1926 14 Sheets-Sheet INVENTOR. Rjf. 1? (WELL.

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July 3, 1928. 1,675,466

R. K. ROWELL AUTOMATIC CAM GRINDING MACHINE Filed Marcus, 1926 1.4 Sheets-Sheet 1o 51K. 1? owz: LL.

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1,675,466 I R. K. ROWELL AUTOMATliC CAM GRINDING MACHINE Filed March 1926 14 Sheets-Sheet ll w QQQ July 3, I928.

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INVENTOR.

R. K. R 0 WELL A ORNEY.

July 3, 1928.

R. K. ROWELL.

AUTOMATIC CAM GRINDING MACHINE Filed March 192 14 Sheets-Sheet INVENTOR. EKRou/ELL.

K AT RNEY.

Julyv3, 1928. 1,675,466

R. K. ROWELL' AUTOMATIC CAM GRINDING MACHINE Filed March 1 l4 Sheets-Sheet l5 M7 A65 my IN VEN TOR.

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\ ATTORNEY.

July 3, 1928. 1,675,466

R. K. ROWELL AUTOMATIC CAM GRINDING MACHINE Filed March 1926 14 Sheets-Sheet l4 i V W 4 m.

In Q g E IN VEN TOR.

RX. [2 owz'zli BY W ' ATTORNEY.

Patented July 3, 1928.

UNITED STATES,

FttittSUE .,466

PATENT, OFFICE.

RALPH K. ROWELL, OF WEST PALM BEACH, FLORIDA, ASSIGNOR TO LANDIS TOOL COMPANY, OF. WAYNESBORO, PENNSYLVANIA, A CORPORATION 01! PENNSYLVANIA.

AUTOMATIC CAM-GBINDIN G HAGHINE.

Application filed larch 6, 1828. Serial No. 82,886.

My said invention relates to an automatic cam grinding machine and it is an object of thesame to provide means whereby an entire cam shaft can be finished to size without any attention from the operator other than that required in starting and stopping the machine.

Another object is to provide means for rotating the master cam and the work in synchronism.

Another object is to provide a means for automatically feeding the wheel into the work at the proper speed and withdraw it when the work is finished.

Anotheer object is to provide means whereby the carriage is moved automatically from a finished cam to the next blank as each cam isfinished, is stopped when the next blank is in front ofthe wheel, and is returned to the starting position when the entire camshaft is finished.

Anotherobject is to provide improved means for reciprocating the wheel spindle in a line parallel with the carriage so as to give a smooth even finish to the work and also to reduce wheel wear.

Referring to the accompanying drawings which are made at art hereof and on which similar reference characters indicate similar parts,

Fig. 1 is a front elevation of the machine A of my invention,

Fig. 2, an end elevation of said machine viewed from the right,

Fig. 3, a front elevation showing the relative position of the master cam and the cam shaft which is being ground,

Fig. 4, a partial longitudinal section of the wheel base and the part of the bed on. which itrests,

Fig. 5, an end elevation of the rear part of the bed viewed from the left an'd showing the wheel feeding motor, m

Fig. 6, an 'end elevation partly in section showing the piping for the wheel feeding motor as seen from the right in Fig. 1,

Fig. 7 a front elevation partly in section showing the oil pump and the piping to both the wheel feeding motor and the traverse motor,

Fig. 8, an end elevation of part of the traversing mechanism for the grinding wheel carriage,

- stock,

Fig. 9, an elevation of the valve operating lever used 'on the carriage traversing mechanism, as seen fromthe left in Fig. 1,

Fig. 10, an elevation of a part of the mechanism for automatically controlling the movement of the, wheel base, as seen from the left in Fig. 1,

. Fig. 11, a horizontal section of said mechanism on line 11-11 in Fig. 10,

Fig. 12, a front elevation of said mechamsm,

Fig. 13, a right elevation of the foot stock,

Fig. 14., a front elevation of said foot Fig. 15, a plan of said foot stock,

Fig. 16, a right elevation of the head stock partly in section showin the method of rotating the work and tie master cam in unison.

Fig. 17, a right hand elevation of the head stock illustrating means for swinging the work toward and away from the wheel so as to grind the cam to the desired shape,

Fig. 18, a longitudinal section of the head stock,

Fig. 19, a longitudinal section of the wheel spindle showing means for reciprocab ing the same,

Fig. 20, a cross-section on line 2020 of Fig. 19, a

Fig. 21, a detail of gearing shown in Fig. 19, i

Fig. 22, a front elevation partly in sec tion of the valve for the traverse motor and the mechanism for operating said valve automatically to start and stop the traverse mechanism,

Fig. 23, a front elevation of the wheel feed motor,-and

Fig. 24, avertical longitudinal section of said motor..--'

In the drawings reference character indicates the fixed bed of the machine which bed supports 'awork-earriage 31 mounted on guides 32 for reciprocation lengthwise of the machine; The bed also supportsa slide base 33 pivoted near its front end at 34 for movement toward and from the work located on the carriage 31 in front of the slide base. The bed furthersupports a fluid motor 35 by means of which the work carriage is moved to and fro on the guides 32, a wheel feed motor 36 for moving the slide base 33 on its fulcrum 34 and various driving and controlling mechanisms hereinafter described.

Work supporting and driving means.

The work carriage 31 bears a table 37 upon which a work supporting bracket 38 is mounted by pivots 39 for movement toward and from a wheel 40 on a wheel base 41 slidingly supported on the slide base 33 for adjustmcnt toward and from the work, as to set the wheel and to compensate for Wear. The bracket 38 and parts carried thereb are roughly triangular in cross section wit the work 42 supported at one corner of the triangle, the master cam shaft 43 at another corner and the pivots 39 at the third corner. The position of the work is determined by a headstock 44 and a footstock 45 carrying respectively centers 46 and 47. The position of the master camshaft is determined by a coupling 48 at one end and a coupling 49 at the other end supported in the bearing 50.

Details of the headstock are shown in Figs. 16 to 18 together with driving means connecting the headstock spindle 51 to a crankshaft 52 which is connected by means of a lug 53 (Figs. 3 and 17) on the coupling 48 to the camshaft. The headstock spindle is driven by a sprocket 54' (Fig. 18) connected by a chain 55 to a sprocket 56 on the work .drlve shaft 57 (Figs. 1 and 2) which in turn is driven by a chain 58 from the change speed shaft 59 operated at various speeds by change speed gearing in a casing 60, the speed being varied by means of a hand-lever 61. The drive shaft of the change speed gearing carries a pulley 62 driven by a belt 63 from a work drive pulle 64 on the main shaft 65, and provided with a belt tightening idler 65". The headstock spindle is divided into two parts spaced from one another and provided with cranks 66 secured to the respective sections by means of dowel pins 67, said cranks carryi'ng crank pins 68 fastened to the cranks by dowel pins 69. An intermediate crank 66 is secured to the adjacent ends of the firstnamed crank pins in similar manner. A work driver 70 is secured to the face plate of the inner spindle section adjacent the center 46.

The crankshaft 52 is provided with cranks and crankpins held together in similar manner to the parts described in connection with the spindle 51. Connecting rods 71 have bearings at opposite ends mounted on adjacent bearings of the crankpins, these connecting rods being arranged parallel to one' another in well-known manner and serving to provide a smooth and uniform drive from the headstock s indle to the crankshaft 52 and hence to tile master camshaft 43. It may be noted that the bracket 72 enclosing the crankshaft 52 and providing bearings for the same is separate from the main which the footst-ock center can be retracted for convenience in dismounting and replacing the work.

he master camshaft is provided with a series of cams corresponding in position to those on the camshaft to be ground while the whole camshaft may be provided only with roughl cast cam blanks which must be roun down to suitable shape. For oscilating the brackets 38 to move the cam blanks toward and from the wheel during grinding operations I have provided a roller 80 mounted in fixed relation on a support secured to an upwardly projecting cover 81 for the traverse motor which cover is fixed in relation to the base or bed 30. The bracket is forced upward by springs 82 (Figs. 1 and 2) into a position where one of the cams of the master camshaft will rest against the periphery of the roller 80. It

will be clear from the foregoing that as the master camshaft rotates in synchronism with the camshaft being operated on the bracket 38 will be oscillated on its fulcrum 39 to move the work toward and from the grinding wheel in a manner to govern precisely the shaping of the successive cams. When the work on a cam is completed the carriage is caused to travel a sufficient distance in one direction, e. g. to the left, to bring the next cam blank into operative relation to the wheel. For thus traversing the carria e I have provided a means comprising the uid motor 35 of which certain details are shown in Figures 1 and 22 and which may be understood to be otherwise of any suitable type preferably having a vane mounted for oscillation between two fixed abutments in a chamber provided with means for admitting fluid alternately at opposite sides of the vane. The motor drives a shaft 83- carrying a pinion 84 whose teeth are in mesh with those of a rack 85 at the under side of the carriage.

Grinding wheel feed.

Itwill be recalled that the grinding wheel is carried by a wheel base or wheel slide 41 mounted on a slide base 33 pivotall supported at 34. For the purpoce of ad usting tilted about their common axes 4. for mov ing the'wheel toward the work to compensate for the decreasing diameter of the work by means comprising a roller 96 (Figs. 2 and 4) underneath the rear end of the slide base resting on-a cam 97. The cam 97 issplincd to the shaft 98 of the work feed motor in a" casing 36, such motor being hereinafter referred. to as the wheel feed motor. This motor has a vane 99 on the shaft 98 arranged for oscillation in a chamber containing an abutment 100' which limits the movement of the vane and through which abutment fluid may be admitted to move the vane in one direction or the other thus rotatingthe cam 97 correspondin ly. A reversing lever 101 controls the'fl ui slide 103 (Fig. 24) is connecte by a roller 104 and a pin 105'to the lever 101 for operating the valve. The pin, also carries a roller 106 bearing on a detent 115 supported at bpposite ends by springs 108 so as to force the-lever 101 toward one "or' the other extreme of its .movement. One purpose of this construction isto' cause the wheel to retreat quickly from the work when a cam is finished.

Automatic controlling means.

In order that the traversemay be made without injury to the wheel or the work it is necessary that one or the other be moved so far from the other in a direction respectively forward or back as to avoid any danger of the work striking the wheel during the'travf erse'. With this object in mind I have pro-- vided interconnected controlling means for the work carriage and the wheel feed lncluding means adapted to act on a forward projection-or roller bar 109 of the bracket 38 in a'manner toimpart an abnormal swinging movement to the .bracket in a direction forretracting the work from the wheel.- This mechanism is illustrated in detail in Figs. 4, 5and8to12.

' A dog 110 is mounted on theperiphery' of a dog-wheel 111 and is adjustable about such periphery by means of a screw 112 having threads engagin teeth indicated at 113 on the outer rim of t e wheel. This dog is adapted to strike a lug 114 on the lever 101, as the work feed motor movesclockwise in Fig. 5, for swinging the lever until the roller 106 passes the point ofthe detent 115 whereupon the springs immediately force admission valve 102 of themotor which may be any suitable type and 'is preferably slidable in a right line.

' about the the lever over the remainder of the path of its movement and reverse the motor. Under circumstances hereinafter described the lever 101 will be held from moving clockwise to the required extent for reversing the movement of the wheel feed motor by means comprising a stop 116 in the path of movement of the lever. The stop 116 is adjustable longitudinally through a rockarm 117 and is provided with a lock nut 118 for locking it in adjusted position. The rockarm 117 is mounted on a rod 119 which is adapted to oscillate in bearings 120. At the front end oftherod 119 a rockarm 121 is provided which rockarm is connected by a link 122 to another rockarm 123 on a rockshaft 124 extending forward through the bed of the machine, or to the right in Fig. 5. At its forward end the shaft carries a rockarm 125; (Fig. 1) connected by a link 126 (Figs. 1, 10.

and12) to a rack 127 adapted to engage a pin 128- on a 'rockarm 129 pivoted at 130 on" a cover 81 and provided at its forward end with a roller 131 contacting with the roller of the bracket 38. A spring 132 draws the A arm 1'29 toward its uppermost position and a plunger 133 forced rearwardly by a spring 134 tends to move the hook 135 into engagement. with the pin 128 on said arm. A fixed abutment 136 (Figs. 10 and 12) on the cover 81 has a cam face cooperating. with a cam face at 137 on the hook 135 to. disengage the same from the pin 128 when the parts are lifted sufliciently high by spring 132.

The dog-wheel 111 or other part moving therewith also carries a dog 138 adjustable peripher of the dog -wheel by a screw 138., said 0g having a nose 139 pivoted at 140 for engagement with a lever 141. (Figs. 4 and 5) pivoted at 142. The dog 139 acts on said lever as the traverse motor moves in a clockwise direction (Fig. 5) to trip the parts operated by said lever the pivotalmounting of the nose permitting the'dog to pass the lever in the contrary direction of movement of the traverse motor without changing its position. As here shown the-dog moves from the solid line osition of F 5 to the dotted 'line position.

he lever 141 is connected by. a link 142 to a lever 143 pivoted at 144 and this in turn is adjustably connected at 145 to a rod 146 slidably mounted in a bearing 147 and carrying a collar 148; -A spring 149 surrounds the rod said spring bearing at one end against collar 148 and at the other against bearing 147 and serving to move the rod and the parts connected therewith normally to the right in Fi 5 or toward the front of 152 to a slidable detent 153 impelled by a spring 154 in a direction to engage under a lateral arm of a lever 155 (Fig. 22).

The piston 156 is slidably mounted in a cylinder 157 formed in the cover 81 and is provided at its lower end with a roller 158 engaging the upper face of the roller bracket 109. At its upper end the chamber 157 has a single port 159 opening into a valve chamber provided with an inlet port 160 (Figs. 1 and 22) and an exhaust port 161. A balanced piston valve 162 is located in said valve chamber and said valve has a stem 163 adjustably connected to the lever 155 with provision for lost motion. The lever 155 has a vertical arm and a laterally extending inclined arm provided at its outer end with a roller 164. A double-acting spring-pressed plunger 165 is mounted approximately in line with said arm so as to force the lever toward its extreme position in either direction of its movement. It will be seen that the detent 153 and the plunger 165 will hold the lever 155 and the valve 162 in the position indicated, so that piston 156 will not move until the detent 153 is retracted. When this occurs the plunger 165 will force the roller 164 downward and move the valve so as to connect the port 159 to the inlet port 160 whereupon the fluid will enter the piston chamber and force the piston down thereby moving the bar 109 downward to' tilt the work supporting bracket 38 away from the wheel.

It will be recalled that the work carriage has a step-by-step or intermittent traversing movement for moving the camshaft so as to bring its successive cam blanks into the field of operation of the grinding wheel 40. and such movement is availed of for the purpose of returnin the work carriage bracket to working position. For this purpose the traversing roller-bar is provided with dogs 166 having forwardly projecting lugs 167 (Figs. 8, 9 and 22). The lever 155 is also provided with a depending finger 169 terminating in a rearwardly projecting lug 168 adapted to cooperate with the lugs 167 in one position thereof (Fig. 9). The finger 169 is pivoted on the lever at 170 in such a manner as to swing to one side in .one relative direction of movement of the roller bar and the lever thus avoiding injury to the relatively movable parts. A pin 171 limits the swingin movement of the finger in a counter-clockwise direction. The lever 155 has a rockarm 172'pivoted thereon, with a roller 173 adapted to contact with the roller bar 109 as it rises. A spring 174 provides a yielding connection between the rockarm 172 and a rigid finger 175 thus cushioning the action of the roller bar on the lever and the valve 162.

It will be seen from the foregoing that when the detent- 153 is withdrawn the lever 155 will be moved clockwise by the plunger 165 so as to open the intake passage 160 to the chamber 157 and thus force the bar down so as to bring its lugs 167 to the level of the lug 168 on the finger 169. As bar 109 now moves to the right in Figure 22 with the work carriage, the appropriate lug 167 will strike the lug 168 (it being understood that the number of dogs 166 corresponds to the number of cam blanks on the camshaft 42). The movement of the carriage will now cause the lever to swing on its pivot in a counter-clockwise direction. and this will move the balanced valve so as to shut off the intake port 160 from port 159 and open a passage from outlet port 161 to port 159. At the same time the spring-pressed plunger 165 is permitted to return into holding position relative to the lever 155.

The movements above described, initiated by engagement of dog 138 with lever 141 in Figure 5 are utilized to govern the operation of the traverse motor. Vhen the bar 109 is forced down by the pressure in the cylinder 157 it acts on a roller 176 (Figs. 8 and 22) on a roller bracket 177 provided with a handle 178. The roller bar is supported on a plunger 17 9 guided for up and down movement in a plunger bracket 180 on the 'cover 81, the movement of the plunger being limited by a stop 181 engaging at its inner end in a slot having parallel vertical branches 181 connected by a horizontal cross-over portion. At its lower end the plunger bears on a laterally extending arm 182 of a three-armed lever 183, the lowermost arm of which is connected to the stem 184 of a balanced piston 185 in a chamber 186 which piston controls the operation of the oscillatory traverse motor 35. It has not been deemed necessary to illustrate details of this motor as it is of well-known type and is shown in other pending applications.

As the roller bar 109 pushes the plunger 179 down and moves the lever 183 counterclockwise the valve 185 uncovers a port 187 leading to an expansion chamber at one side of the vane of the traverse motor and admits fluid under pressure through an intake port 188 to said expansion chamber. Such movement of the valve also opens a passage from the port 189 to the outlet passage 190 of the motor for escape of fluid from the non-working side of the motor. The contrary movement of the 'roller bar and plunger permits a spring 191 to move the lever 183 in a clockwise direction thus moving the Valve 185 to the left to an extent sufiiricut only to bring the valve into the position il-' pleted and has been replaced by a new one the carriage mustbe returned to its original or starting position and for this purpose the handle 178 is turned to the left sufficiently to disengage the pin 181 from the shoulder between the branches 181, of the slot in which the pin moves.. The plunger 179 may now rise to the full extent of its movement and the lever 183 may consequently-be moved in a counter-clockwise direction by the spring 191 to such an extent as to open a passage from the inlet port 192 to the port 189 for moving the motor in a direction to return the work carriage to its original position. At the same time the valve opens a way from the port 187 t o the outlet 190 to permit escape of fhiid from the non-working side of the traverse motor.

Pump.

The device of my invention is provided with a rotary pump 193 driven by a sprocket 7 chain 194 assing over a sprocket 195 on the pump sha .and a sprocket 196 on the main shaft of the machine. The pump has an intake 197 and an exhaust pipe 198 communicating with. the inlet ports 188 and 192 of the traverse motor and with the inlet por tion 160 for the piston chamber 157. An exhaust pipe 199 returns the exhaust fluid from the exhaust ports 185 and 187 of the traverse motor and the exhaust port 161 of the piston chamber to the reservoir 200' at the bottom of the machine. A manually operated valve 201 serves to cut ofi the supply of pressure fluid to the traverse motor when desired. A pipe 202 leads from the pipe 198 to the wheel feed motor 36 and an ex-- haust pipe 203 brings back the surplus fluid from said motor to 'the'reservoir 200. A relief valve 204 may be spring-pressed in a direction to open it and is closed by a hand lever 221. This lever provides means whereby the. operator can permit the fluid to return temporarily to the reservoir without operating the motors and may also provide for relief of excessive pressure so that the speed of the pump need not be changed nor need the pump be stopped because of temporary cessation of operation of the machine. A manually controlled valve 205 in a the pipe 202 serves to cut out the operation of the wheel feed motor when desired.

Wheel lira/verse.

It is found desirable to give a limited traverse'to the grinding wheel for reducing the wear on the whel as much as possible and to give a smooth even finish to the work. For this purpose the grinding wheel spindle 90 is provided with a worm'206 meshing with teeth on a pinion 207 which is loose on a shaft 208. The shaft has eccentric portions at each end engaging forks in levers 209 pivoted at 210. These levers are connect'ed by means of links 211 to a bronze col-' lar 212 surrounding the shaft, said forks being pivoted to the collar at 213. The collar is held against endwise movement on the shaft by means of a pair of washers 214, the washer at the left restingagainst a shoulder on the spindle and the washer at the right being held in place by a nut 215. The gear 207 is caused'to rotate with the shaft 208 by means of a clutch member 216 engaging a clutch face on the gear. A coiled spring 217 tends to separate the clutch faces and a screw 218 having an outer hand wheel .219 bears at its inner end against a pin 220 which is mounted at its ends in the clutch member 216 so that rotation of the hand wheel moves said clutch member into engagement with the worm gear.

It will be seen that rotation of the spindle and the wheel will turn the worm gear '207 and the eccentrics rotating therewith thus swinging the levers 20.9 through their connections to the collar 212 moving the shaft endwise to a limited extent. This reciprocating motion may be stopped by separating the clutch member 216 from the worm gear through the medium of the hand Wheel 219 and screw 218.

Operation. In the operation of my device a camshaft is placed between the work centers, as indicated in Figure 3, the work carriage having been previously brought to its position farthest to the right so as to begin operations on a cam blank. The starting lever 221 is now moved to the right to close thevalve 204 and fluid under pressure passesto the feed motor, power being also applied to the wheel in ordinary manner. The wheel feed motor rotates the cam. 97 in a counter-clockwise directionas seen in Figure 5, or clockwise as seen in Figure 2, the headstock is driven as above described causing the bracket 58 to rock in accordance with the contour of the master cam on the camshaft 43 and the operation proceeds in ordinary manner until the cam is ground to the desired size at which time the dog 110 strikes the pin 114 on lever 101 and swings the lever in a clockwise direction to a position in which the upper end of the lever moves to the left of the position shown in Figure 5.

As a result of such movement of the lever the valve 102 is now in a position to admit fluid to that side of the wheel feed motor which will cause the motor to turn back-- ward, i. e., in a direction to lower the slide base. During forward movement {of the motor the dog 138 was moving counterclockwise in Figure 5 with the dog wheel and it moves beyond the dotted line position in said figure and past the nose ofthe lever 142, the pivoted end portion of the dog permitting the dog to pass said nose wlthout ment with said pin.

tripping the lever. On the reverse movement 0 the motor the dog wheel is moved clockwise and such movement continues until dog.110 strikes pin 114 and moves lever 101 to the position indicated in solid lines in Fi re 5 where it abuts against a stop 116 w ich prevents further movement of the lever for the time being and cuts off the fluid from both sides of the motor. Just prior to the attainment of this position by the dog 110, the dog 138 passed the nose of lever 141 in a clockwise direction and therefore moved said lever about its pivot 142. As a result of such movement the lever 141 acting through the train of connections 142, 143, 146, and 151 retracts the latch 153 from lever 155 (Fig. 22). Thereupon the plunger acts on the lever through the roller 164 to move the valve 162 to the right and permit pressure fluid to enter the cylinder 157, moving piston 156 so as to force roller bar 109 down and so set the traverse motor in operation by acting on arm 179 oflever 183. vThe lateral movement of the bar with the work carriage causes the next lug 167, which has now been lowered to the proper level, to strike lug 168 and tilt lever 155 out of the way of latch 153 which then is moved back to latching position by spring 154. At the same time the lever moves the valve 162 to stop the flow of pressure fluid and opens the wayto outlet 161 thus permitting the piston 156 and the bar 109 to rise. As the bar rises the spring 191 moves the. lever 183 and valve 185 so as to stop the traverse motor.

When the bar 109 is forced down it acts through roller 131 to lower lever 129 until pin 128 is low enough to be engaged by hook 135, when; the hook is moved into engage- As the bar rises the rod 126 is moved up and through the train of elements previously described, rocks shaft 119 to move stop 116 out of the way of lever 101 whereupon the lever moves further over under the pressure of detent .115 until it is in position to cause the motor to move in a clockwise direction to again raise the slide base and so repeat the c cle ofoperations.

It will be obvious to those skilled in the art that various changes may be made in my device without departing from the spirit of the invention, and I, therefore, do not limit myself to what is shown in the drawings and described in the specification, but only as set forth in the appended claims.

Having thus fully described m said invention, what I claim as new an desire to for tilting said bracket away from the grinding wheel, substantially as set forth.

2. In a cam grinding machine, a rotary wheel, a tilting support therefor, a bracket tiltableon an axis parallel .to that of the wheel, means on said bracket for supporting a camshaft, amaster camshaft arranged parallel to the axis of said wheel, and a fixed follower on a fixed support coacting with the cams on the master camshaft for tilting the bracket, and means for tilting the said bracket away from the grinding wheel, substantially as set/forth.

3. In a cam grinding machine, a rotary wheel, a tilting support therefor, a bracket tiltable on an axis parallel to that of the wheel, means on said bracket for supporting a camshaft, a master camshaft arranged parallel to the axis of said Wheel, a follower on a fixed support coacting with the cams on the master camshaft for tilting the bracket, and resilient means serving to tilt the bracket and move the work toward the wheel, and additional means for tilting the bracket away from the grinding wheel, substantially as set forth.

4. In a cam grinding machine, a rotar wheel, a tilting support therefor, a work carriage, means on the carriage for supporting and rotating a camshaft, a cam for tilting the wheel supporting means, and an oscillatory fluid motor for driving said camshaft alternately in opposite directions, substantially as setforth.

5; In a cam grinding machine, a rotary wheel, a tilting-support therefor, a work carriage, means on the carriage for supporting and rotating a camshaft, a cam for tilting the wheel supporting means, an oscillatory fluid motor for driving said cam shaft alternately in opposite directions, a traversing work carriage, and means .for moving with said motor for controlling the movements of the work carriage, substantially as set forth.

6. In a cam grinding machine, a rotary Wheel, a tilting support therefor, a work carriage, means on the carriage for supporting and rotating a camshaft, a cam for tilting the wheel supporting means, an oscilcarriage, means on t e carriage for supporting and rotating :1 camshaft, a cam for tilt ing the wheel supportin means, an oscillatory ,fluid motor for riving said cam- I 

